public class Main2 {
    //变量命名模式：
    //数据类型 变量名 = 初始值；
//    int a = 10;
//    double d = 3.14;
//    char c = 'A';
//    boolean n = true;

    public static void main(String[] args) {
        int a = 10;
        double d = 3.14;
        char c = 'A';
        boolean n = true;

        System.out.println(a);
        System.out.println(d);
        System.out.println(c);
        System.out.println(n);


        a = 100;
        System.out.println(a);

        int a1 = 10, a2 = 20, a3 = 30;
        System.out.println(a1);
        System.out.println(a2);
        System.out.println(a3);

    }
}
